| staunch(adjective, calm, strong, secure, firm) |
| staying put(expression, adjective, calm, strong, substantial) |
| steady-going(adjective, firm, solid, steady, substantial) |
| sticky(adjective, still, passive, motionless, stationary) |
| stuck(adjective, still, passive, motionless, stationary) |
| sturdy(adjective, calm, strong, secure, firm) |
| sure(adjective, calm, strong, secure, firm) |
| sustainable |
| systematic(adjective, calm, smooth, steady, temperate) |
| together(adjective, calm, strong, secure, firm) |
| tough(adjective, calm, strong, solid, steady) |
| trim(adjective, calm, smooth, flat, plain) |
| trimmed(adjective, calm, smooth, flat, plain) |
| true(adjective, direct, smooth, right, flat) |
| unbendable |
| undeviating(adjective, direct, smooth, right, flat) |
| undiversified(adjective, normal, even, rigid, inflexible) |
| unflappable(adjective, calm, dull, smooth, steady) |
| unmodifiable(adjective, normal, even, rigid, inflexible) |
| unmoving(adjective, strong, secure, still, substantial) |